Balanced vibratory mechanism



Oct. 7, 1969 A. K. FERRARA BALANCED VIBRATOHY MECHANISM United States Patent O 3,470,754 BALANCED VIBRATORY MECHANISM Achille K. Ferrara, Elmwood Park, Ill., assignor to Ultramatic Equipment Co., Chicago, Ill., a corporation of Iilinois Filed Nov. 20, 1967, Ser. No. 684,259 Int. Cl. F16h 33/20; B07b N44; Flc 33/36 U.S. Cl. 74-26 6 Claims ABSTRACT OF THE DISCLOSURE For use in a vibratory machine in which certain ma chine elements are to be vibrated, a balanced vibratory mechanism for effecting vibration of the machine elements to be vibrated, the balanced vibratoryv mechanism comprising a shaft which is adapted to be rotatably driven upon its central axis by a `prime mover, cylindrical eccentric cam means mounted to the shaft, bearing means intermediate the cam means and a housing to permit rotation of the cam means relative to the housing, and counterbalanceing means for centrifugally counterbalancing the shaft, the housing being adapted to be mechanically linked to the machine elements to be vibrated such that vibratory motion of the housing is transmitted to the machine elements to be vibrated.

BACKGROUND OF THE INVENTION This invention pertains generally to an improved vi bratory mechanism for effecting vibration of the machine elements to be vibrated in a vibratory machine, and particularly to a balanced vibratory mechanism characterized by a shaft which is adapted to be rotatably driven about its oentral axis.

One example of a vibratory machine of this type, in which certain machine elements are to be vibrated, is a vibratory screen separator in which at least one separating screen is to be vibrated. Such vibratory screen separators are commonly used fo-r sizing gravel and for many other purposes. Another example, is a vibratory finishing machine in which a tub for workpieces and finishing media is to be vibrated. Such vibratory finishing machines are commonly used for deburring and polishing metal castings and for many other purposes, the finishing media usually comprising abrasive chips or stones of a natural material such as limestone or of a manufactured material, and the finishing media usually being bathed with a detergent solution to wash away fine abrasive particles and burr particles. Another example is a vibratory pelletizing mill in which a vat for work material and balls is to be vibrated. Such vibratory pelletizing mills are commonly used for grinding and dispersing ceramic clays, minerals, and other materials, and for many other purposes, a plurality of balls of steel or of some other hard material usually lbeing employed in these vibratory machines. Still other examples include vibratory conveyors, vibratory parts feeders, and the like.

There is in each of the aforementioned examples a need for a vibratory mechanism for effecting vibration of the machine elements to be vibrated. The conventional vibratory mechanism for this purpose comprises a shaft, bearing means engaging the shaft and supporting a housing to permit rotation of the shaft relative to the housing, and unbalanced weights mounted to the shaft for slinging rotation around the shaft to cause the shaft to vibrate eccentrically as the shaft is rotated, thereby to cause the housing to vibrate as the shaft is rotated. The housing is mechanically linked to the machine elements to be vibrated such that vibratory motion of the housing is transmitted to the machine elements to be vibrated.

3,470,754 Patented Oct. 7, 1969 In a conventional vibrato-ry mechanism, because the shaft vibrates as it rotates, a flexible coupling, a pair of universal joints connected by an intermediate linking shaft, or similar connecting means must be used to connect the eccentrically rotatable shaft to a prime mover. Also, double-row spherical-roller bearings are commonly employed in the conventional vibratory mechanism. It is difficult to adjust the tolerance of 4bearings of this type to compensate for wear.

SUMMARY OF THE INVENTION It is the object of this invention to provide a balanced vibratory mechanism for effecting vibration of the machine elements to be vibrated in a vibratory machine, the balanced vibratory mechanism comprising a shaft having a central axis about which the shaft is rotatable.

Such a balanced vibratory mechanism comprises, in addition to the shaft having a central axis about which the shaft is rotatable, cylindrical eccentric cam means having a central axis and being eccentrically mounted to the shaft for conjoint rotation with the shaft upon the central axis of the shaft, a housing having cylindrical inner surface means surrounding and being spaced from the cam means, bearing means intermediate the cam means and the inner surface means of the housing to permit rotation of the cam means relative to the housing, and counter-balancing means for centrifugally counterbalancing the shaft. In operation, the central axis of the shaft, about which the shaft is rotatable, remains stationary with respect to a fixed frame of reference found in the vibratory machine, whereby pulleys, gears or similar connecting means may be used to connect the shaft to a prime mover. It is unnecessary to use a flexible coupling, a pair of universal joints connected by an intermediate shaft, or the like, as in a conventional vibratory mechamsm.

It is one feature of this invention that the cylindrical eccentric cam means may comprise first and second cylindrical eccentric cam members which are coaxial and axially spaced along the shaft, the cylindrical inner surface means of the housing comprises first and second cylindrical inner surface portions which surround and are spaced from the respective first and second cam members, the bearing means comprising first `and second rolling-contact bearing means which are intermediate the respective first and second cam members and the respective first and second inner surface portions of the housing to permit rotation of the first and second cam members relative to the housing.

It is another feature of this invention that such first and second rolling-contact bearing means may comprise respectively first and second tapered-roller bearings, the first tapered-roller bearing having an inner race member which is circumferentially fitted upon the first cam member and an outer race member which is circumferentially fitted within the first inner surface portion of the housing, the second tapered-roller bearing having an inner race member which is circumferentially fitted upon the second cam member and outer race member which is circumferentially fitted within the second inner surface portion of the housing, the vibratory mechanism further comprising adjusting means for adjusting the axial tolerances of the first and second tapered roller bearings.

It is another feature of this invention that the outer race member of such first tapered-roller bearing and the outer race member of such second tapered-roler bearing may be slidably fitted within the respective rst and second inner surface portions of the housing, the outer race members being restrained from axially inward movement together along the respective first and second inner surface portions of the housing, the inner race member of the first tapered-roller bearing being slidably fitted upon the first cam member and being restrained from axially outward movement along the first cam member, the inner race member of the second tapered-roller bearing being slidably fitted upon the second cam member, the respective inner race members being adapted to be drawn relatively together and apart to adjust the axial tolerances of the first and second tapered-roller bearings, the second cam member having an axially outwardly extending threaded portion, the adjusting means comprising lock-nut means adjustably threadably engaging the threaded portion of Ithe second cam member and restraining in inner race member of the second tapered-roller bearing from axially outward movement along the second cam member.

Other objects, advantages, and features of this invention will be evident from the following description, with the aid of the accompanying drawings, of a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING In the drawings:

FIGURE 1 is a longitudinal elevational view of a balanced vibratory mechanism embodying the principles of this invention, with portions thereof being broken away and shown in section;

FIGURE 2 is an exploded sectional detail of lock nut means forming part of the balanced vibratory mechanism of FIGURE 1; and

FIGURE 3 is a sectional view taken substantially along section line 3-3 in FIGURE 1, looking in the direction indicated by the arrow, an example of a connection of the housing of the balanced vibratory mechanism to the machine elements to be vibrated in a vibratory machine being sketched in phantom lines.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIGURE 1, the balanced vibratory mechanism comprises a cylindrical shaft 12 having a central longitudinal axis about which the shaft 12 s rotatable. A first cylindrical eccentric cam member 14 and a second cylindrical essentric cam member 16 are mounted to the shaft 12 for conjoint rotation with the shaft 12 about the central axis of the shaft 12. The cam members 14 and 16 are coaxial and axially spaced along the shaft 12, the first cam member 14 being adjacent to the left-hand free end 18 of the shaft 12, the second cam member 16 being located at an intermediate portion 20 of the shaft 12. The cam members 14 and 16 are held in place on the shaft 12 in any suitable manner, such as by means of set screws (not shown). The right-hand end (broken away) of the shaft 12 is adapted to be connected through pulleys, gears, or other suitable means, to a prime mover such as an electric motor or an industrial power takeoff.

The balanced vibratory mechanism 10 further comprises a housing 22. As shown, the housing 22 includes a first bell member 24, a second bell member 26, and a tubular connecting member 28, which are welded together. The first bell member 24 of the housing 22 has a first cylindrical inner surface por-tion 30, which surrounds and is spaced from the first cam member 14, and the second bell member 26 of the housing 22 has a second cylindrical inner surface portion 32, which surrounds and is spaced from the second cam member 16, the shaft 12 being freely rotatable within the respective bell members 24 and 26 and the tubular connecting member 28 of the housing 22. The housing 22 is adapted to be connected in any suitable manner, such as by means of brackets holding the respective bell members 24 and 26 of the housing 22, to the machine elements to be vibrated in a vibratory machine, as described. An example of such a connection will be described hereinafter with reference to FIGURE 3.

The balanced vibratory mechanism 10 further comprises a first tapered-roller bearing 34 and a second tapered-roller bearing 36, which are intermediate the respective first and second cam members 14 and 16 and the respective first and second inner surface portions 30 and 32 of the housing 22 to permit rotation of the first and second cam members 14 and 16 relative to the housing 22. The first tapered-roller bearing 34 has an inner race member 38, which is circumferentially fitted upon the first cam member 14, and an outer race member 40, which is circumferentially fitted within the first inner surface portion 30 of the first bell member 24 of the housing 22. The second tapered-roller bearing 36 has an inner race member 42, which is circumferentially fitted upon the second cam member 16, and an outer race member 44, which is circumferentially fitted within the second inner surface portion 32 of the second bell member 26 of the housing 22. The housing 22 is not connected to the shaft 12 and -the cam members 14 and 16 otherwise than through the first and second tapered-roller bearings 34 and 36.

The outer race member 40 of the first tapered-roller bearing 34 and the outer race member 44 of the second tapered roller bearing 36 are slidably fitted within the respective first and second inner surface portions 30 and 32 and are restrained from axially inward movement together along the respective first and second inner surface portions 30 and 32, the outer race member 40 of the first tapered roller bearing 34 by an annular shoulder 46 of the bell 24 of the housing 22, and the outer race member 44 of the second tapered roller bearing 36 by an annular shoulder 48 inthe bell 26 of the housing 22.

The inner race member 38 of the first tapered-roller bearing 34 is slidably fitted upon the first cam member 14 and is restrained from axially outward movement along the first cam member 14 by an annular flange 50 on the first cam member 14. It is to be understood that the tapered roller bearing 34 is axially oriented so as to be capable of being axially loaded between the shoulder 46 and the flange 50, the opposite axial orientation being unsuitable, as is evident from the manner in which the outer and inner race members 38 and 40 are restrained.

The inner race member 42 of the second tapered-roller bearing 36 is slidably fitted upon the second cam member 16. Adjusting means 52 for adjusting the axial tolerance of the first and second tapered-roller bearings 34 and 36 comprises a lock-nut means 54 adjustably threadably engaging an axially outwardly extending threaded portion 56 of the second cam member 16 and restraining the inner race member 42 of the second tapered-roller bearing 36 from axially outward movement along the second cam member 16. It is to be understood that the tapered-roller bearing 36 is axially oriented so as to be capable of being axially loaded between the shoulder 48 and the lock-nut means 54, the opposite axial orientation being unsuitable, as is evident from the manner n which the outer and inner race members 38 and 40 are restrained.

The lock-nut means 54, which is of a conventional type, comprises an internally threaded generally annular lock nut S8, which has one or more circumferentially spaced transverse peripheral grooves 60a, 60b, etc., and a generally annular lock washer 62, which has a plurality of generally outwardly extending circumferentially spaced outer tabs 64a, 64b, etc., and which has a generally axially inwardly extending inner tab or key 66. The second cam member 16 is formed with a keyway 68, which receives the key 66 when the lock washer 62 is positioned around the second cam member 16 against the inner race member 42 of the second tapered bearing means 36. The keyway 68 is slightly longer than the key 66 to permit limited axial movement of the lock washer 62 along the second cam member 16. The lock washer 62, which thus is keyed to the second cam member 16, is held against the inner race member 42 of the second tapered-roller bearing 36 by the lock nut 58, which threadably engages the threaded portion 56 of the second cam member 16. Thus, the lock-nut means 54 restrains the inner race member 42 of the second tapered-roller bearing 36 from axially outward movement along the second cam member 16. The threaded portion S6 of the second cam member 16 is slightly longer than the lock nut 58 to permit limited adjustment of the threaded position of the lock nut 58 with respect to the threaded portion 56 of the second cam member 16, thereby to permit adjustment of the axial tolerances of the first and second tapered-roller bearings 34 and 36.

Adjusting of the axial tolerance of the first and second tapered roller bearings 34 and 36 may be accomplished by turning the lock nut 58 upon the threaded portion 56 of the second cam member 16 to adjust the axial spacing of the lock nut 58 and the annular flange 50 on the first cam member 14, the axial spacing of the shoulders 46 and 48 being fixed. The minimum axial spacing of the respective outer race members 40 and 44 is determined by the fixed axial spacing of ther'shoulders 46 and 48, and the maximum axial spacing of the inner race members 38 and 42 is determined by the adjusted axial spacing between the fiange 50 on the first cam member 14 and the lock washer 62 axially outwardly engaging the lock nut 58. Such minimum and maximum axial spacings determine the axial tolerances of the first and second tapered-roller bearings 34 and 36. It is characteristic of tapered-roller bearings that the shaft'and housing tolerances thereof are determined by the axial tolerances thereof. Thus, such minimum and maximum axial spacings determine the shaft and housing tolerances of the first and second tapered-roller bearings.

The lock-nut means 54 should be locked to the threaded portion 56 of the second cam member 16, and thus to the shaft 12, by bending one of the outer tabs 64a, 64b, etc., of the lock washer 62, which is keyed to the second cam member 16 by the key 66 in the keyway 68, into one of the peripheral grooves 60a, 60h, etc., of the lock nut 58. In the drawing, the outer tab 64a of the lock washer 62 is shown to be bent into the peripheral groove 60a of the lock nut 58, the unbent position of the outer tab 64a being shown in dashed lines.

In operation of the adjusting means 52, the lock nut 58 may be turned by means of a conventional torquewrench (or other suitable implement) to such turned position with respect to the threaded portion 56 of the second cam member 16 as provides the proper axial tolerances to the first and second tapered roller bearings 34 and 36. The axial tolerances may be measured by suitable micrometer means or other gauging means. The lock nut 58 should then be advanced or retracted, if necessary, to the nearest turned position at which one of the outer tabs 64a, 64b, etc., of the lock washer 62 may be bent into one of the peripheral grooves 60a, 60h, etc., of the lock nut 58 to lock the lock washer 62 to the lock nut 58 and thereby to lock the lock-nut means 54 to the threaded portion 56 of the second cam member 16. Thereafter, throughout the useful lives of the respective first and second tapered roller bearings 34 and 36, as normal nondestructive bearing wear is incurred, further advancement of the lock nut 50 may be made by means of the torquewrench (or other implement) to restore the proper axial tolerances to the first and second tapered-roller bearings 34 and 36, the bent outer tab 64a (or other) of the lock washer 62 having been bent back to release the lock nut 58. The -use of a torque-wrench permits the lock nut 58 to be tightened with a torque essentially equal to the torque with which'it initially had been tightened, the latter torque serving as a measure of the axial tolerances of the first and second tapered roller bearings 34 and 36. After such adjustment has been made, the lock washer 62 may be relocked to the lock nut 58, as described.

A first end plate 70, which has an enlarged central opening 72, closes the bell member 24 of the housing 22 and is mounted in place by a plurality of screws 74, which extend through apertures 76 in the first end plate 70 and threadably engage threaded sockets 78 in the bell 24 of the housing 22. The first cam member 14 has an axially outwardly extending cylindrical end portion 80, which tits through the central opening 72 in the first end plate 70. A second end plate 82, which has an enlarged central opening 84, closes the bell member 26 of the housing 22 and is mounted in place by a plurality of screws 86, which extend through threaded apertures 88 in the second end plate 82 and threadably engage threaded sockets 90 in the bell 26 of the housing 22. The second cam member 16 has an axially outwardly extending cylindrical end portion 92 which fits through the central opening 84 in the second end plate 82. Suitably rotary packing means (not shown) may be provided around the central opening 72 between the first end plate 70 and the end portion 80 of the first cam member 14 and around the central opening 84 between the second end plate 82 and the end portion 92 of the second cam member 16, in which case suitable bearing lubricant may be introduced in the pocket 94 between the first end plate 70 and the first tapered roller bearing 34, in the pocket 96 between the second end plate 82 and the second tapered roller bearing 36, and in the pocket 98 between the respective first and second tapered roller bearings 34 and 36.

The housing 22, the machine elements to be vibrated by the balanced vibratory mechanism 10, and the first and second cam members 14 and 16 centrifugally unbalance the shaft 12 principally adjacent to the first and second cam members 14 and 16. First counterbalancing means 100, which generally opposes the centrifugal imbalance adjacent to the first cam member 14, and second counterbalancing means 102, which generally opposes the centrifugal imbalance adjacent to the second cam member 16, are provided for generally centrifugally balancing the shaft 12,

The first counterbalancing means 100 comprises a ring member 104, which is fitted over the shaft 12 generally against lthe end portion of the first cam member 14 and fiush with the free end 18 of the shaft 12, a radially extending arm member 106, which is welded as at 108 to the ring member 104, and a plurality of mass-loading means 110, which are suitably mounted to the arm member 106 by means of bolts 112. The ring member 104 is held in place on the shaft 12 by means of a set sere-W 114 which extends through an aperture 116 in the ring member and threadably engages a threaded socket 118 in the shaft 12, the ring member 104 being turned with respect to the shaft 12 such that the first counterbalancing means opposes the eccentricity of the first and second cam members 14 and 16. In order to retain the ring member 104 against the end portion 80 of the first cam member 14, a retaining disc 120 is mounted to the shaft 12 flush with the free end 18 thereof and with the ring member 104 by means of a bolt 122, which is employed over a lock washer 124, and which passes through a suitable central aperture 126 in the retaining disc 120 and threadably engages a suitable coaxial threaded socket 128 in the shaft 12.

The second counterbalancing means 102, which is generally similar to the first counterbalancing means 100, comprises a ring member 130, which is fitted over the shaft 12 generally against the end portion 92 of the second cam member 16, a radially extending arm member 132, which is welded as at 134 to the ring member 130, and a plurality of mass-loading means 136, which are suitably mounted to the arm member 132 by means of bolts 138. The ring member is held in place on the shaft 12 by means of a set screw 140 which extends through an aperture 142 in the ring member 130 and threadably engages a threaded socket 144 in the shaft 12, the ring member 130 being turned with respect to the shaft 12 such that the second counterbalancing means 102 opposes the eccentricity of the first and second cam members 14 and 16. In order to retain the ring member 130 against the end portion 92 of the cam member 16, an additional lock-nut means 146. is locked to an axially outwardly located threaded portion 148 of the shaft 12. The

lock-nut means 146, which is generally similar to the locknut means 54, comprises an internally threaded generally annular lock nut 150, which has one or more circumferentially spaced transverse peripheral grooves 152a, 152b, etc., and a generally annular lock 4washer 154, which has a plurality of generally outwardly directed outer tabs 156a, 156b, etc., and which has a generally axially inwardly extending inner tab or key 158. The shaft 12 is formed with a keyway 160 which receives the key 158 when the lock washer 154 is positioned around the shaft 12 against the ring member 130. The lock washer 154, which thus is keyed to the shaft 12, is held against ring member 130 by the lock nut 150, which threadably engages the threaded portion 148 of the shaft 12. The locknut means 146 should be locked to the threaded portion 148 of the shaft 12 by bending one of the outer tabs 15611, 15811, etc., of the lock washer 154, which is keyed to the shaft 12 by the key 158 in the keyway 160, into one of the peripheral grooves 152a, 152b, etc., of the lock nut 150. In the drawing, the outer tab 156a of the lock washer 154 is shown to be bent into the peripheral groove 152a of the lock nut 150, the unbent position of the outer tab 156a being shown in dashed lines. The bent outer tab 156:1 (or other) may be bent back to release the lock nut 150.

By proper selection of the masses of the mass-loading means 110 and 136 and the lengths of the arm members 106 and 132 of the respective first and second counterbalancing means 100 and 102, the shaft 12 may be generally centrifugally counterbalanced under normal running conditions which result from normal loads on the machine elements to be vibrated by the balanced vibratory mechanism 10. This substantially eliminates any tendency of the shaft 12 to vibrate or wobble with respect to the central axis about which the shaft 12 is rotatable.

An example of a connection of the housing 22 of the balanced vibratory mechanism to the machine elements to be vibrated in a vibratory machine is sketched in phantom lines in FIGURE 3. Reference number 162 represents a tub for workpieces and finishing media in a vibratory machine of the type mentioned hereinbefore. The tub 162 is suitably mounted on a bed of springs 164. A first bracket 166 rigidly connects the bell member 26 of the housing 22 to the tub 162. The first bracket 166 has a lower mounting portion 168, which is suitably mounted by means of screws (not shown) or otherwise to the bell member 26 of the housing 22, an upper mounting portion 170, which is suitably mounted to the underside of the tub 162 by means of screws (not shown) or otherwise, and an upright portion 172, which is integral with the upper mounting portion 168 and with the lower mounting portion 170. A second bracket (not shown), which is similar to the first bracket 166, similarly connects the bell member 24 of the housing 22 to the tub 162. The foregoing should be understood merely as an example of the Way in which a balanced vibratory mechanism may be applied. In other applications quite different connections may be used. For example, in some applications a nonrigid connection may be useful.

Modifications and variations within the scope of this invention will be suggested by this disclosure to those skilled in the art. Accordingly, the scope of this invention should be determined from the following claims.

I claim:

1. A balanced vibratory mechanism comprising a cylindrical shaft having a central longitudinal axis about which the shaft is rotatable, a first and a second cylindrical eccentric cam member which are mounted to the shaft for conjoint rotation with the shaft upon the central axis of the shaft and are coaxial and axially spaced along the shaft, a housing having a first and a second cylindrical inner surface portion which surround and are spaced from the respective first and second cam members, a first and a second tapered-roller bearing intermediate the respective first and second cam members and the respective first and second inner surface portions of the housing to permit rotation of the first and second cam members relative to the housing, counterbalancing means for generally centrifugally counterbalancing the shaft, and adjusting means for adjusting the axial tolerances of the first and second tapered roller bearings, the first tapered-roller bearing having an inner race member which is circumferentially fitted upon the first cam member and an outer race member which is circumferentially fitted within the first inner surface portion of the housing, the second tapered-roller bearing having an inner race member which is circumferentially fitted within the second inner surface portion of the housing.

2. The balanced vibratory mechanism of claim 1 wherein the outer race member of the first tapered-roller bearing and the outer race member of the second taperedroller bearing are slidably fitted within the respective first and second inner surface portions of the housing and are restrained from axially inward movement together along the respective first and second inner surface portions of the housing, the inner race member of the first tapered-roller bearing being slidably fitted upon the first cam member and being restrained from axially outward movement along the first cam member, the inner race member of the second tapered-roller bearing being slidably fitted upon the second cam member, the second cam member having an axially outwardly extending threaded portion, the adjusting means comprising lock-nut means adjustably threadably engaging the threaded portion of the second cam member and restraining the race member of the second tapered-roller bearing from axially outward movement along the second cam member.

3. The balanced vibratory mechanism of claim 2 wherein the lock-nut means comprises a lock nut which has at least one transverse peripheral groove and a lock washer which is keyed to the threaded portion of the second cam member, the lock washer having a plurality of circumferentially spaced outer tabs one of which may be bent into the transverse peripheral groove of the lock nut to lock the lock-nut means to the threaded portion of the second cam member.

4. The balanced vibratory mechanism of claim 2 wherein the lock-nut means comprises a lock nut which has a plurality of transverse peripheral grooves and a lock washer which is keyed to the threaded portion of the second cam member, the lock washer having a plurality of circumferentially spaced outer tabs one of which may be bent into one of the transverse peripheral grooves in the lock nut to lock the lock-nut means to the threaded portion of the second cam member.

5. The balanced vibratory mechanism of claim 1 wherein the outer race member of the first tapered-roller bearing and the outer race member of the second taperedroller bearing are slidably fitted within the respective first and second inner surface portions of the housing and are restrained from axially inward movement together along the respective first and second inner surface portions of the housing, the inner race member of the first taperedroller bearing and the inner race member of the second tapered-roller bearing being slidably fitted upon the respective first and second cam members and being restrained from axially outward movement along the respective first and second cam members.

6. The balanced vibratory mechanism of claim 1 wherein the outer race member of the first tapered-roller bearing and the outer face member of the second taperedroller bearing are slidably fitted within the respective first and second inner surface portions of the housing and are restrained from axially inward movement together along the respective first and second inner surface portions of the housing, the inner race member of the `first taperedroller bearing being slidably fitted upon the first cam member and being restrained from axially outward movement along the first cam member, the inner race member of the second tapered-roller bearing being slidably tted upon the second cam member, the adjusting means restraining the inner race member of the second tapered-roller bearing from axially outward movement along the second cam member.

References Cited UNITED STATES PATENTS 1,583,785 5/1926 Evans 30s-62 1,949,703 3/1934 Wemaufer 209-3677 2,784,598 3/1957 Larsen 7L2v6 10 FRED C. MATTERN, JR., Primary Examiner W. S. RATLIFF, IR., Assistant Examiner U.S. Cl. X.R. 

